1. Field of the Invention
The invention relates to technology of a nut arranging apparatus that is an apparatus for arranging nuts in a multi-axis temporary tightening tool.
2. Description of Related Art
There are cases in which a work that is an object of assembly is fixed to a portion to which the work is to be assembled, using a plurality of screwing members (such as nuts and bolts), as is the case when fastening a wheel of a tire to a hub using a plurality of nuts. For example, in the work of fixing a wheel to a hub using nuts, when tightening the nuts, a worker typically first screws the nuts by hand, one at a time, by only a few threads onto stud bolts that are implanted in the hub, and then performs the final tightening of the nuts at a predetermined torque using a tool such as a torque wrench. In the main description below, screwing together a screwing member such as a nut or a bolt to a screwable member such as a stud bolt or a nut by only a few threads before final tightening will be referred to as “temporary tightening”.
However, if a worker temporarily tightens the nuts by hand one at a time, it takes time and is laborious, so a tool (a so-called multi-axis temporary tightening tool) capable of temporarily tightening a plurality of nuts simultaneously has been developed in order to perform temporary tightening work efficiently. For example, the technology described in Japanese Patent Application Publication No. 2006-205274 (JP 2006-205274 A) that will be described below is well known. The term “multi-axis temporary tightening tool” referred to here is a tool suited for the use of simultaneously “temporarily tightening” a plurality of screwing members (such as bolts and nuts), but the use is not limited to temporarily tightening screwing members. For example, when there is little need for torque control, the multi-axis temporary tightening tool may also be used to simultaneously final-tighten a plurality of screwing members, or may be used to simultaneously loosen a plurality of screwing members that are fastened together, or the like.
The multi-axis temporary tightening tool according to the related art described in JP 2006-205274 A includes a driving gear that rotates by driving means, a plurality of driven gears, a toothed belt that is wound around the driving gear and the plurality of driven gears and transmits the rotation of the driving gear to the plurality of driven gears, and a plurality of sockets that are connected to the plurality of driven gears and engage with bolts or nuts. The driving gear is arranged in the center of a main body portion of the multi-axis temporary tightening tool, and the plurality of driven gears and sockets are arranged around the driving gear in the main body portion. With this kind of structure, the plurality of sockets are able to be simultaneously rotatably driven, thus making it possible to temporarily tighten the plurality of bolts or nuts or the like simultaneously, by inputting rotary force to the driving gear.
However, when temporarily tightening nuts using the multi-axis temporary tightening tool according to the related art described in JP 2006-205274 A, the nuts must be arranged beforehand in each of the plurality of sockets. Conventionally, a worker manually arranges the nuts in the sockets, so the work of temporary tightening takes time and is laborious.
Also conventionally, an apparatus for adjusting the postures of the nuts or the like and supplying the nuts or the like to a desired position has been developed. For example, the technology described in Japanese Patent Application Publication No. 2007-55787 (JP 2007-55787 A) that will be described below is well known. With the supplying apparatus (i.e., a thin plate-shaped work separating and removing apparatus) for nuts or the like according to the related art described in JP 2007-55787 A, an inclined bottom surface is provided in a hopper, and a separation chute that can be raised and lowered is provided adjacent to the lowest portion of the bottom surface. By raising and lowering the separation chute, an individual thin plate-shaped work is engaged and sequentially transferred from the hopper by its own weight through the separation chute and a fixed chute. This kind of supply apparatus for nuts or the like is able to separate and remove thin plate-shaped works one by one with a simple structure. Moreover, the hopper is not vibrated nor is the thin plate-shaped work swept up by a scraper, so noise from vibration and the like is suppressed, which improves the work environment. In addition, the thin plate-shaped work is able to be prevented from being damaged.
However, it is difficult to use a supply apparatus for nuts or the like according to related art, such as the supply apparatus described in JP 2007-55787 A, for the purpose of arranging nuts in positions corresponding to the sockets of a multi-axis temporary tightening tool. Also, an apparatus capable of efficiently arranging nuts in positions corresponding to the sockets does not exist, so when using a conventional multi-axis temporary tightening tool, a worker must arrange the nuts in the sockets by hand, and as a result, temporary tightening work takes time and is laborious.